Serum cystatin C 1.12 mg/L is within the normal range and usually does not matter. Serum cystatin C ranges from 0.6 to 2.5 mg/L in adults. Therefore, serum cystatin C1.12mg/L is within the normal range and usually does not matter. The original urinary cystatin C in the proximal tubule is almost completely taken up by the epithelial cells, decomposition, do not return to the blood, only a small amount of urinary excretion, therefore, the serum cystatin C level is reflecting the glomerular filtration function of a sensitive and specific indicator. Clinically, the severity of renal damage is usually judged on the basis of glomerular filtration rate. The glomerular filtration rate cannot be determined simply by knowing the value of cystatin C. In clinical practice, it is usually calculated by various formulas using various laboratory data, such as urea, creatinine, cystatin C, etc., combined with the patient’s gender, age, ethnicity and other information. If patients find that cystatin C is elevated, it is recommended to go to regular hospitals in time, complete the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.